The invention relates to a modular data storage system comprising: a plurality of identical data carriers having a recording layer in which data can be recorded in coded form and from which said data can be read; at least one recorder apparatus provided with supporting means for supporting a data carrier in a recorder operating position and provided with recording and/or read means for recording and/or reading the data on or from a data carrier which is in the recorder operating position; at least one storage module for storing a plurality of said data carriers close to and adjacent each other, which storage module comprises a module frame; an internal transport device accommodated within the module frame of the storage module for the transport of data carriers between a storage position and a transfer position at the back of the storage module; an external transport device, cooperatively associated with the storage module at the storage module back, for the transport of data carriers between said transfer position at the back of the storage module and a loading position near a recorder apparatus; an enclosure for the external transport device located at the back of the storage module; and at least one electronic control unit, associated with the storage module, for coordinating and controlling the transport of the data carriers between their storage positions in the storage module and the loading position near the recorder apparatus; the storage modules, when the storage system comprises a plurality of such modules, being arrangeable on top of and adjacent each other in optional configurations to form enclosed modular systems with a data-storage capacity adapted to specific requirements, the external transport device cooperating with each storage module at the rear and the enclosure of the external transport device being adapted to the resulting external dimensions of said configuration of combined storage modules.
Such a modular data storage device for the storage of computer data is known from U.S. Pat. No. 3,715,040. The data carriers comprise magnetic-tape reels provided with an amount of magnetic tape and the recorder apparatus comprises a professional magnetic-tape recorder suitable for the purpose. The magnetic-tape recorder is of the type frequently employed in peripheral equipment used in conjunction with larger computer systems. The recorder comprises two reel spindles, permitting transport of a magnetic tape from a reel on the one reel spindle to another reel on the other reel spindle. A full magnetic-tape reel is manually placed onto the one reel spindle, after which the magnetic tape is fed to the reel on the second reel spindle via a plurality of tape guides and magnetic heads and is attached to said second reel. Subsequently, the recorder may be put into operation for reading the data on the magnetic tape or for recording data on the magnetic tape. After use, the magnetic tape is rewound onto the first reel and the reel containing the tape is removed from the magnetic-tape recorder and may then be stored for subsequent use.
In this known data storage system, the external transport device comprises two sections. A first section of the external transport device is located at the back of a plurality of stacked storage modules. Data carriers, specifically, magnetic tape reels comprising reels with magnetic tapes wound thereon, are moved into an upper position in a vertical direction along the backs of the storage modules. There the magnetic tape reel is taken over by a horizontal section of the external transport device, which actuates a plurality of vertical sections of the external transport device and which can bring a magnetic-tape reel into the loading position near a recorder. Said horizontal section is only suitable for bringing magnetic-tape reels into a loading position near a single recorder apparatus. The magnetic tape reels are moved to a position above the recorder apparatus where they can be removed from the horizontal section of the external transport device by an operator. Subsequently, the magnetic tape reel is manually placed onto the recorder apparatus. When a magnetic tape reel is removed from the recorder by an operator it may be placed back in the loading position on the horizontal section of the external transport device. Since the transport devices transfer the magnetic-tape reels to a location near the recorder, this causes the operator a certain amount of work. However, the magnetic-tape reels still have to be handled manually by an operator, so that only the location of the storage position of the relevant magnetic-tape reel and the transport of said reel between the storage module and the recorder are effected automatically under control of the control unit. The external transport device appears to be unsuitable for cooperation with a plurality of magnetic-tape recorders, unless intricate further steps, which are not revealed in said U.S. Patent are taken, such as adding branches to the horizontal section of the external transport device, complete with shunts and an intricate control system.